In case you don't know what a selfie is, Oxford Dictionaries defines it as:

(n.) a photograph that one has taken of oneself, typically with a smartphone or webcam and uploaded to a social media website.

It's not a new word -- its origins date to a 2002 posting in an Australian Web forum, according to Reuters-- but that doesn't matter. "The Word of the Year need not have beencoined within the past 12 months and it does not have to be a word thatwill stick around for a good length of time," Judy Pearsall, editorialdirector for Oxford Dictionaries, tells Reuters.

According to Oxford's editors, use of the word has gone up a staggering 17,000% since 2012, Reuters reports.